Four-year old: Mommy, what are those squishy things that are haging next to my peanut? There are two of them.
Mommy: Those are your testicles.
Four-year old: Ohhhh…testicles. What do they do?
Mommy: You know what? I think that’s a good question for Daddy.
Four-year old: Oh right. Because Daddy has the biggest peanut in the family, so he’ll know how they work.

Yes, we also talk about dinosaurs, superheroes, dragon-sightings, and how to reassemble a thermostat dismantled by curious three-year old hands (hint: you don’t). But a significant proportion of our conversations revolve around body parts and bad smells, and the bad smells made by body parts. They will outgrow it, though, right? At least by the time they turn forty-three?